The present invention generally relates to a rotary valve and more particularly, to a rotary valve which selectively provides fluid to a cylinder assembly, effective to allow a vehicle or other apparatus to be easily turned and maneuvered.
A rotary valve is used to selectively communicate fluid and pressure to a cylinder assembly in response to the receipt of torque from a steering wheel or shaft, effective to allow for relatively easy steering and/or maneuvering of a vehicle. One type of such a rotary valve is referred to as a xe2x80x9cBishopxe2x80x9d valve which is described, by way of example and without limitation, in the publication entitled Development of the Bishop ATS Rotary Valve which is authored by Mr. Andrew Thomas, which is published by the Society of Automotive Engineers, which may be referenced by Library of Congress Number ISSN0148-7191, and which is fully and completely incorporated herein by reference, word for word and paragraph for paragraph.
Particularly, such a rotary valve a sleeve member which journals on an input shaft member. Each member typically and respectively has axially extending blind ended slots which cooperatively form throttling orifices which deliver fluid and concomitantly created pressure to one of two opposed ends of a cylinder assembly, thereby causing the cylinder assembly to assist in the turning and maneuvering of the vehicle.
While the rotary valve does allow for the selective communication of fluid and pressure to the cylinder assembly, it may suffer from some disadvantages. For example and without limitation, the use of the previously delineated orifices may cause the valve to resonant or xe2x80x9cvibratexe2x80x9d, thereby imparting undesired vibrations to the steering wheel and to the vehicle driver. Moreover, the orifices also cause cavitation and other forms of noise which may be undesirably communicated into the vehicular passenger compartment.
It may therefore be desirable to provide a rotary valve which overcomes some or all of the previously delineated drawbacks of prior rotary valves and which concomitantly allows a vehicle to be easily steered and maneuvered.
It is a first object of the present invention to provide a rotary valve which overcomes some or all of the previously delineated drawbacks of prior rotary valves and which, by way of example and without limitation, concomitantly allows a vehicle to be easily steered and maneuvered.
It is a second object of the present invention to provide a rotary valve which overcomes some or all of the previously delineated drawbacks of prior valves and which, by way of example and without limitation, operates in a substantially quiet manner.
It is a third object of the present invention to provide a rotary valve which overcomes some or all of the previously delineated drawbacks of prior valve assemblies and which, by way of example and without limitation, substantially prevents resonance from occurring and/or reduces the likelihood of resonance from occurring during the operation of the valve.
According to a first aspect of the present invention, a rotary valve is provided and includes a first port which receives fluid from a source and a second port which receives the fluid and which communicates the fluid to the source, the second port being substantially identical to the first port.
According to a second aspect of the present invention, a rotary valve is provided which receives torque and which provides a certain pressure which increases in accordance with an increase of the supplied torque.
According to a third aspect of the present invention, a method is provided for reducing the likelihood of resonance from occurring in a rotary valve of the type having at least an inlet port through which fluid is communicated and an outlet port through which the fluid exits the valve, the method including the step of constricting the outlet port.
These and other features, aspects, and advantages of the present invention will become apparent from a reading of the following detailed description of the preferred embodiment of the invention and by reference to the following drawings.